The present invention is directed toward a ski exercise machine and more particularly, toward a cross-country type ski machine which includes a sensor system capable of monitoring exercise performance and which can generate corresponding exercise information.
In Applicant's prior application, Ser. No. 153,418, it was explained that it is important when exercising to have some degree of monitoring or feedback of the exerciser's progress or performance. Information such as the distance traveled or the speed is essential. The prior application described a conventional stepper and explained that in conventional systems, the monitoring equipment consists essentially of a magnetic reed switch which turns on and off as a step passes the same. In addition to the mechanical drawbacks of a magnetic reed switch and failures due to the mechanics thereof, the prior application points out that a reed switch serves only as a counter since it can only generate "on" or "off" signals.
Thus, some exercise information, such as the amount of calories consumed, cannot be determined accurately because this requires additional information which the reed switch cannot provide such as the extent of the angular movement of the foot pedals of the stepper. Similarly, the reed switch, when used with stepper machines, cannot sense the speed of the movement of the foot pedals. Thus, a slow, short rotation of the foot pedals cannot be distinguished from a fast, long rotation of the same. As a result, the amount of exercise effort determined is inaccurate.
In order to improve on conventional stepper machines, Applicant's prior application describes a sensor system which more accurately monitors exercise performance and is capable of generating more precise exercise information. The sensor system described therein is comprised of a photo-detecting unit, a slotted wheel and an information control unit. The photo-detecting unit is mounted on the stepper frame assembly and includes photo emitters and photo receivers aligned therewith and adapted to receive light from the emitters. The slotted wheel is mounted so as to be rotatable along with the movement of one of the foot pedals and has a flange member which extends between the photo emitters and the photo receivers. Movement of the foot pedal moves the slotted wheel so that the slots therein interrupt the light passing from the photo emitters to the photo receivers thereby generating an electrical signal which represents the position, movement and speed of movement of the foot pedal. This provides much more accurate information than conventional systems which allows for more precise calculations of exercise information.
Conventional cross-country ski exercise machines suffer from substantially the same drawbacks as conventional steppers. That is, such ski machines which normally employ a pair of foot support means which are mounted so as to move forwardly and backwardly lack a sensor system that is dependable and will provide necessary exercise information. Such conventional systems include sensors that also utilize magnetic reed switches which suffer from the same drawbacks as the reed switches utilized with conventional steppers. That is, they may suffer from mechanical breakdown after prolonged use and are also capable of generating only an "on" or "off" signal. They cannot provide information such as the full extent of movement of the foot support means or the speed of movement thereof.